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-rw-r--r--src/passes/MergeBlocks.cpp124
-rw-r--r--src/tools/binaryen-shell.cpp77
-rw-r--r--src/wasm-s-parser.h2
3 files changed, 164 insertions, 39 deletions
diff --git a/src/passes/MergeBlocks.cpp b/src/passes/MergeBlocks.cpp
index d26817e18..5794e1379 100644
--- a/src/passes/MergeBlocks.cpp
+++ b/src/passes/MergeBlocks.cpp
@@ -17,9 +17,53 @@
//
// Merges blocks to their parents.
//
+// We also restructure blocks in order to enable such merging. For
+// example,
+//
+// (i32.store
+// (block
+// (call $foo)
+// (i32.load (i32.const 100))
+// )
+// (i32.const 0)
+// )
+//
+// can be transformed into
+//
+// (block
+// (call $foo)
+// (i32.store
+// (block
+// (i32.load (i32.const 100))
+// )
+// (i32.const 0)
+// )
+// )
+//
+// after which the internal block can go away, and
+// the new external block might be mergeable. This is always
+// worth it if the internal block ends up with 1 item.
+// For the second operand,
+//
+// (i32.store
+// (i32.const 100)
+// (block
+// (call $foo)
+// (i32.load (i32.const 200))
+// )
+// )
+//
+// The order of operations requires that the first execute
+// before. We can do the same operation, but only if the
+// first has no side effects, or the code we are moving out
+// has no side effects.
+// If we can do this to both operands, we can generate a
+// single outside block.
+//
#include <wasm.h>
#include <pass.h>
+#include <ast_utils.h>
namespace wasm {
@@ -50,6 +94,86 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks, Visitor<MergeBloc
}
}
}
+
+ Block* optimize(Expression* curr, Expression*& child, Block* outer = nullptr, Expression** dependency1 = nullptr, Expression** dependency2 = nullptr) {
+ if (!child) return outer;
+ if (dependency1 && *dependency1 && EffectAnalyzer(*dependency1).hasSideEffects()) return outer;
+ if (dependency2 && *dependency2 && EffectAnalyzer(*dependency2).hasSideEffects()) return outer;
+ if (auto* block = child->dynCast<Block>()) {
+ if (block->list.size() >= 2) {
+ child = block->list.back();
+ if (outer == nullptr) {
+ // reuse the block, move it out
+ block->list.back() = curr;
+ block->finalize(); // last block element was our input, and is now our output, which may differ TODO optimize
+ replaceCurrent(block);
+ return block;
+ } else {
+ // append to an existing outer block
+ assert(outer->list.back() == curr);
+ outer->list.pop_back();
+ for (Index i = 0; i < block->list.size() - 1; i++) {
+ outer->list.push_back(block->list[i]);
+ }
+ outer->list.push_back(curr);
+ }
+ }
+ }
+ return outer;
+ }
+
+ void visitUnary(Unary* curr) {
+ optimize(curr, curr->value);
+ }
+ void visitSetLocal(SetLocal* curr) {
+ optimize(curr, curr->value);
+ }
+ void visitLoad(Load* curr) {
+ optimize(curr, curr->ptr);
+ }
+ void visitReturn(Return* curr) {
+ optimize(curr, curr->value);
+ }
+
+ void visitBinary(Binary* curr) {
+ optimize(curr, curr->right, optimize(curr, curr->left), &curr->left);
+ }
+ void visitStore(Store* curr) {
+ optimize(curr, curr->value, optimize(curr, curr->ptr), &curr->ptr);
+ }
+
+ void visitSelect(Select* curr) {
+ optimize(curr, curr->condition, optimize(curr, curr->ifFalse, optimize(curr, curr->ifTrue), &curr->ifTrue), &curr->ifTrue, &curr->ifFalse);
+ }
+
+ void visitBreak(Break* curr) {
+ optimize(curr, curr->condition, optimize(curr, curr->value), &curr->value);
+ }
+ void visitSwitch(Switch* curr) {
+ optimize(curr, curr->condition, optimize(curr, curr->value), &curr->value);
+ }
+
+ template<typename T>
+ void handleCall(T* curr, Block* outer = nullptr) {
+ for (Index i = 0; i < curr->operands.size(); i++) {
+ outer = optimize(curr, curr->operands[i], outer);
+ if (EffectAnalyzer(curr->operands[i]).hasSideEffects()) return;
+ }
+ }
+
+ void visitCall(Call* curr) {
+ handleCall(curr);
+ }
+
+ void visitCallImport(CallImport* curr) {
+ handleCall(curr);
+ }
+
+ void visitCallIndirect(CallIndirect* curr) {
+ auto* outer = optimize(curr, curr->target);
+ if (EffectAnalyzer(curr->target).hasSideEffects()) return;
+ handleCall(curr, outer);
+ }
};
static RegisterPass<MergeBlocks> registerPass("merge-blocks", "merges blocks to their parents");
diff --git a/src/tools/binaryen-shell.cpp b/src/tools/binaryen-shell.cpp
index 8f5fbe4e5..96f506934 100644
--- a/src/tools/binaryen-shell.cpp
+++ b/src/tools/binaryen-shell.cpp
@@ -198,50 +198,51 @@ int main(int argc, const char* argv[]) {
auto input(read_file<std::vector<char>>(options.extra["infile"], Flags::Text, options.debug ? Flags::Debug : Flags::Release));
- if (options.debug) std::cerr << "parsing text to s-expressions...\n";
- SExpressionParser parser(input.data());
- Element& root = *parser.root;
-
- // A .wast may have multiple modules, with some asserts after them
bool checked = false;
- size_t i = 0;
- while (i < root.size()) {
- Element& curr = *root[i];
- IString id = curr[0]->str();
- if (id == MODULE) {
- if (options.debug) std::cerr << "parsing s-expressions to wasm...\n";
- Module wasm;
- std::unique_ptr<SExpressionWasmBuilder> builder;
- try {
+
+ try {
+ if (options.debug) std::cerr << "parsing text to s-expressions...\n";
+ SExpressionParser parser(input.data());
+ Element& root = *parser.root;
+
+ // A .wast may have multiple modules, with some asserts after them
+ size_t i = 0;
+ while (i < root.size()) {
+ Element& curr = *root[i];
+ IString id = curr[0]->str();
+ if (id == MODULE) {
+ if (options.debug) std::cerr << "parsing s-expressions to wasm...\n";
+ Module wasm;
+ std::unique_ptr<SExpressionWasmBuilder> builder;
builder = make_unique<SExpressionWasmBuilder>(wasm, *root[i]);
- } catch (ParseException& p) {
- p.dump(std::cerr);
- abort();
- }
- i++;
- assert(WasmValidator().validate(wasm));
-
- MixedArena moreModuleAllocations;
-
- if (passes.size() > 0) {
- if (options.debug) std::cerr << "running passes...\n";
- PassRunner passRunner(&wasm);
- if (options.debug) passRunner.setDebug(true);
- for (auto& passName : passes) {
- if (passName == "O") {
- passRunner.addDefaultOptimizationPasses();
- } else {
- passRunner.add(passName);
+ i++;
+ assert(WasmValidator().validate(wasm));
+
+ MixedArena moreModuleAllocations;
+
+ if (passes.size() > 0) {
+ if (options.debug) std::cerr << "running passes...\n";
+ PassRunner passRunner(&wasm);
+ if (options.debug) passRunner.setDebug(true);
+ for (auto& passName : passes) {
+ if (passName == "O") {
+ passRunner.addDefaultOptimizationPasses();
+ } else {
+ passRunner.add(passName);
+ }
}
+ passRunner.run();
+ assert(WasmValidator().validate(wasm));
}
- passRunner.run();
- assert(WasmValidator().validate(wasm));
- }
- run_asserts(&i, &checked, &wasm, &root, &builder, entry);
- } else {
- run_asserts(&i, &checked, nullptr, &root, nullptr, entry);
+ run_asserts(&i, &checked, &wasm, &root, &builder, entry);
+ } else {
+ run_asserts(&i, &checked, nullptr, &root, nullptr, entry);
+ }
}
+ } catch (ParseException& p) {
+ p.dump(std::cerr);
+ abort();
}
if (checked) {
diff --git a/src/wasm-s-parser.h b/src/wasm-s-parser.h
index dae321866..bb6fe3fd4 100644
--- a/src/wasm-s-parser.h
+++ b/src/wasm-s-parser.h
@@ -173,7 +173,7 @@ private:
curr->list().push_back(parseString());
}
}
- assert(stack.size() == 0);
+ if (stack.size() != 0) throw ParseException("stack is not empty", curr->line, curr->col);
return curr;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-08 06:37:05 +0000